| Message ID | 1413794777-32220-2-git-send-email-boris.brezillon@free-electrons.com |
|---|---|
| State | Accepted |
| Commit | 62d956dc3e11138c5ffd4b2c62e4f909c5180a12 |
| Headers | show |
On Mon, Oct 20, 2014 at 10:46:14AM +0200, Boris Brezillon wrote: > read_page_raw and write_page_raw method description is not clear enough. > It clearly specifies that ECC correction should not be involved but does > not talk about specific layout (by layout I mean where in-band and > out-of-band data are stored on the NAND media) used by NAND/ECC > controllers. > > Those specific layouts might impact MTD users and thus should be hidden (as > already done in the standard NAND_ECC_HW_SYNDROME implementation). > > Clearly state this constraint in the nand_ecc_ctrl struct documentation. > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > --- > include/linux/mtd/nand.h | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > index e4d451e..b14d190 100644 > --- a/include/linux/mtd/nand.h > +++ b/include/linux/mtd/nand.h > @@ -455,8 +455,21 @@ struct nand_hw_control { > * be provided if an hardware ECC is available > * @calculate: function for ECC calculation or readback from ECC hardware > * @correct: function for ECC correction, matching to ECC generator (sw/hw) > - * @read_page_raw: function to read a raw page without ECC > - * @write_page_raw: function to write a raw page without ECC > + * @read_page_raw: function to read a raw page without ECC. This function > + * should hide the specific layout used by the ECC > + * controller and always return contiguous in-band and > + * out-of-band data even if they're not stored > + * contiguously on the NAND chip (e.g. > + * NAND_ECC_HW_SYNDROME interleaves in-band and > + * out-of-band data). > + * @write_page_raw: function to write a raw page without ECC. This function > + * should hide the specific layout used by the ECC > + * controller and consider the passed data as contiguous > + * in-band and out-of-band data. ECC controller is > + * responsible for doing the appropriate transformations > + * to adapt to its specific layout (e.g. > + * NAND_ECC_HW_SYNDROME interleaves in-band and > + * out-of-band data). > * @read_page: function to read a page according to the ECC generator > * requirements; returns maximum number of bitflips corrected in > * any single ECC step, 0 if bitflips uncorrectable, -EIO hw error > -- > 1.9.1 > thanks for this patch. hi Brian, what's your opinion about this patch? thanks Huang Shijie
On Sat, Oct 25, 2014 at 11:55:27AM +0800, Huang Shijie wrote: > On Mon, Oct 20, 2014 at 10:46:14AM +0200, Boris Brezillon wrote: > > read_page_raw and write_page_raw method description is not clear enough. > > It clearly specifies that ECC correction should not be involved but does > > not talk about specific layout (by layout I mean where in-band and > > out-of-band data are stored on the NAND media) used by NAND/ECC > > controllers. > > > > Those specific layouts might impact MTD users and thus should be hidden (as > > already done in the standard NAND_ECC_HW_SYNDROME implementation). > > > > Clearly state this constraint in the nand_ecc_ctrl struct documentation. > > > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > --- > > include/linux/mtd/nand.h | 17 +++++++++++++++-- > > 1 file changed, 15 insertions(+), 2 deletions(-) > > > > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > > index e4d451e..b14d190 100644 > > --- a/include/linux/mtd/nand.h > > +++ b/include/linux/mtd/nand.h > > @@ -455,8 +455,21 @@ struct nand_hw_control { > > * be provided if an hardware ECC is available > > * @calculate: function for ECC calculation or readback from ECC hardware > > * @correct: function for ECC correction, matching to ECC generator (sw/hw) > > - * @read_page_raw: function to read a raw page without ECC > > - * @write_page_raw: function to write a raw page without ECC > > + * @read_page_raw: function to read a raw page without ECC. This function > > + * should hide the specific layout used by the ECC > > + * controller and always return contiguous in-band and > > + * out-of-band data even if they're not stored > > + * contiguously on the NAND chip (e.g. > > + * NAND_ECC_HW_SYNDROME interleaves in-band and > > + * out-of-band data). > > + * @write_page_raw: function to write a raw page without ECC. This function > > + * should hide the specific layout used by the ECC > > + * controller and consider the passed data as contiguous > > + * in-band and out-of-band data. ECC controller is > > + * responsible for doing the appropriate transformations > > + * to adapt to its specific layout (e.g. > > + * NAND_ECC_HW_SYNDROME interleaves in-band and > > + * out-of-band data). > > * @read_page: function to read a page according to the ECC generator > > * requirements; returns maximum number of bitflips corrected in > > * any single ECC step, 0 if bitflips uncorrectable, -EIO hw error > > -- > > 1.9.1 > > > thanks for this patch. > > hi Brian, what's your opinion about this patch? I like the concept. It might be more succinctly described along the lines of "the same layout as the non-raw versions (i.e., .read_page / .write_page)". But the extra words may help for being more explicit. I haven't taken a closer look at the other patches yet. Brian
On Mon, Oct 20, 2014 at 10:46:14AM +0200, Boris Brezillon wrote: > read_page_raw and write_page_raw method description is not clear enough. > It clearly specifies that ECC correction should not be involved but does > not talk about specific layout (by layout I mean where in-band and > out-of-band data are stored on the NAND media) used by NAND/ECC > controllers. > > Those specific layouts might impact MTD users and thus should be hidden (as > already done in the standard NAND_ECC_HW_SYNDROME implementation). > > Clearly state this constraint in the nand_ecc_ctrl struct documentation. > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Pushed this patch to l2-mtd.git. Thanks! Brian
On Thu, Nov 20, 2014 at 12:06:27AM -0800, Brian Norris wrote: > On Mon, Oct 20, 2014 at 10:46:14AM +0200, Boris Brezillon wrote: > > read_page_raw and write_page_raw method description is not clear enough. > > It clearly specifies that ECC correction should not be involved but does > > not talk about specific layout (by layout I mean where in-band and > > out-of-band data are stored on the NAND media) used by NAND/ECC > > controllers. > > > > Those specific layouts might impact MTD users and thus should be hidden (as > > already done in the standard NAND_ECC_HW_SYNDROME implementation). > > > > Clearly state this constraint in the nand_ecc_ctrl struct documentation. > > > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > Pushed this patch to l2-mtd.git. Thanks! thanks. I am really happy you can merge this patch. Huang Shijie
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index e4d451e..b14d190 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -455,8 +455,21 @@ struct nand_hw_control { * be provided if an hardware ECC is available * @calculate: function for ECC calculation or readback from ECC hardware * @correct: function for ECC correction, matching to ECC generator (sw/hw) - * @read_page_raw: function to read a raw page without ECC - * @write_page_raw: function to write a raw page without ECC + * @read_page_raw: function to read a raw page without ECC. This function + * should hide the specific layout used by the ECC + * controller and always return contiguous in-band and + * out-of-band data even if they're not stored + * contiguously on the NAND chip (e.g. + * NAND_ECC_HW_SYNDROME interleaves in-band and + * out-of-band data). + * @write_page_raw: function to write a raw page without ECC. This function + * should hide the specific layout used by the ECC + * controller and consider the passed data as contiguous + * in-band and out-of-band data. ECC controller is + * responsible for doing the appropriate transformations + * to adapt to its specific layout (e.g. + * NAND_ECC_HW_SYNDROME interleaves in-band and + * out-of-band data). * @read_page: function to read a page according to the ECC generator * requirements; returns maximum number of bitflips corrected in * any single ECC step, 0 if bitflips uncorrectable, -EIO hw error
read_page_raw and write_page_raw method description is not clear enough. It clearly specifies that ECC correction should not be involved but does not talk about specific layout (by layout I mean where in-band and out-of-band data are stored on the NAND media) used by NAND/ECC controllers. Those specific layouts might impact MTD users and thus should be hidden (as already done in the standard NAND_ECC_HW_SYNDROME implementation). Clearly state this constraint in the nand_ecc_ctrl struct documentation. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> --- include/linux/mtd/nand.h | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)